c. table salt is a metalloid with properties of both reactants
Reactants are what is changed in the chemical reaction. They go before the arrow when you wrote the equation. Products are what is formed when the chemical reaction occurs. Products always contain the same elements as the reactants, but they might be rearranged because of the reaction. In this picture, you can see that the reactants go before the arrow, and the products go after.
From the given chemical formula or equation, it can be seen that for every molecule of the given chemical, there are 2 moles of NH4+ ions. Thus, to calculate for the concentration of the ion in the solution, we multiply 0.30M by 2 giving as an answer of 0.60M.
Answer:
1.6 g/cm3
Explanation:
The formula for Density is actually D=m/v
m= 12.9g
v= 8 cm3

The unit is grams per centimeters cubed or g/cm3
(If you use the formula given in the question it would be D=0.62)